Top for desks and the like



Dec. 16, 1930. R. H. MCLEOD 1,784,969

TOP FOR DESKS AND THE LIKE Filed Jan. 5, 1928 W I W INVENTOR Raymond/7fMcLeod %MMMI ATTORN EY so as to have asoft, agreeable effect on thePatented Dec. 16, 193 0 UNITED, 8mm

RAYMOND H. McLEOi), OELAUREL, MISSISSIPPI, ASSIGNORY T0 MoLEOD runnirunnCOMPANY, or LAUREnMIssIssIPrI, A oonronArioiv or ivrIssIssIPrr Tor EonnEs s aim rnnmxn Application filed i'fanuaryi, 1928, 7 Serial No, 2{14,588."

'My present invention is shown as embodied in a wooden top for desks,tables and the like,- but certain featuresof the invention may be usedfor other purposes a My invention is particularly applicable to theconstruction of a table or desk top of the type intended to be finishedor painted in solid colors rather than varnished or polished to bringout the grain of the Wood. For instance, a top for a tableor desk-madein accordance with my present invention maybe stained or painted asuitable shade of green eyes of the user; ora solid paint back-ground ofany desired color maybe further decorated with a suitable pattern orpicture applied by handpainting, printing or well known transferprocess;In either case, the

color coating may be protected by pyroxylin and, if desired, the glossof the latter may be dulled by applying floor wax or similar material.

As concerns the use of solid color paints restful to the eye, myinvention may be con-V sidered as an improvement over the linoleumtopped desks and tables which are now much In vogue. As now made, suchtops are expensive, not only on account of the cost of by what is calledcross-banding by gluing sheets of veneer to oppositefaces of the core,the grain of'the veneer running widthwise 0f the table, that is, atright angles-to the grain of said'core- Over this again there is anotherlayer of veneer, usually thinner, having the grain running the samedirection as the grain of the core. This makes what is called a five-plybuilt-up'top. ,VVhen the core is carefully made and-the twolayers ofveneer thus applied to both "faces thereof, a'fairly nonwarpingstructure is produced, onfthe upper fa'ce 'of which is applied the sheetof linoleum of the desired color. This product is of course expensive,and also, as I have discovered, is unsatisfactory because, although thetwo plies or even one ply of veneer on each face of the core may beadequate to prevent warplng, the non-warping effect isdueto'the symmetryof the tensionapplied by the tensile strength of the veneer on the 7 topsurface being exactly equal to the'tension on't-he bottom surface Butwhen linoleum is subsequently cemented to one of these surfaces and notto the other, the equality of tension 'isupset. Such equality might bere stored bygluing a similar layer-of linoleum on the bottom face of thestructure,but the expense would be prohibitive.

By my invention, I am able to produce a table or desk top farsuperior tothose of the prior art as concerns non-warping quality and Wearresisting quality and affording a painted surface which'may imitatelinoleum or may be ornamentally painted to afford yet more original andpleasing effects. Y 7 According to my preferred method, Isub stituteforthe top layers-(one or two layers of veeneer' andone layer oflinoleum) a sin glelayer of a dense composition of a peculiar kindhaving a practically negligible temperature expansion and substantiallyno humidity expansion, the: principal reason :for the lat-' ter beingthat the composition, is non-'hygror scopic besides being substantiallywaterproof under the conditions ofuse.

While there may beothercompositions hav ing the above qualities, Iprefer, to use a-composition made of long fiber, resinous wood pulp,the, natural lignins or resins of the wood, preferably constituting thebinder. The pulp is preferably that produced by a wellknown processfofsubjecting woodenchips to the action of steam or water under suitablepressures whereby the wood is charged with Water superheated to a hightemperature without burning the fiber or its natural binder material,whereupon the pressure-being abruptly released, the fibers are tornapartby the explosive effect of the instantaneously' released steam.- Bysuitable ,7

methods, such shredded lfiber pulp can be less than water.

felted and then formed into dense sheets by applying heavy follow-uppressure of, say 400 lbs. to 600 lbs. or more per square inch, with asuitable degree of. heat to expel water and weld the fibers by thenatural gums or resins of the wood as the binder. In the preferredproduct, the natural wood constituents in the pulp have been compressedto a specific gravity which may be and preferably is greater thanthatofwater, eventhough the i wood emp loy ed'be of specific gravity-much Itspeculiarity is remark- V able tensile strength combinedwithremarkablestiffness and limited elasticity, that is to say, it iselastic underslight deflection, but .if its limited flexing elasticity be; exceeded,it snaps after the manner of a brittle substance. These qualitiespeculiarly adapt this composition for use-as a tensile and compressioncross-banding material for a composite core in place of theveneers'heretofore used. Moreover, as the product is un1- for both facesof the core.

As before stated, the materialis practically without expansion orClOIlllIilClllOIlLlIlClGI ordinary ranges of atmospheric heat and memberor platen, and is finished to great den- According to my preferredmethod, aboardcold and dryness or humidity. V

When made by the preferred process, one

face of the composition,preferably the upper surface, contacts with asmooth compression sity and smoothness either with or without alubricant or finish such-as parafline. Preferably, thesurface in contactwith theothercompression member, is carried by or com pressed againstsome sort of reticulated sur-',

face such as a fine wire netting on which it has been felted. Thesurface being marked or grooved by the reticulation is peculiarlyadapted to take the glue which must be .used for securing it to the coreor filler. v

lVith the'above or similar sheet composition for cross-banding, I havediscovered 1 that it is .not'necessary to build up a core by gluedtongue andgrooveor dovetail joints.

like sheet of thecomposition of the proper size for the table top islaid on the assembly table, with aqwire-m a'rkedor raw surface Vupward,"and the filler strips corresponding twelve hours. The longstaple, natural wood to the ,core are simply coated with glue on theiropposite faces and laid on the board until the area is filled up withsuch strips, whereupon asimilar board of the composition is laidovertheupper surfacesfof said strips, preferably smooth face upward.This threeplystructure is placed in clamps, subjected togreat pressureand so remains for,say,

composition described above is peculiarly adapted to absorb considerablequantities of assured, 7

tailed or glued to one another. Short pieces with irregular ends andwood having worm holes or similar defects-may bev used if the majorportion of it is sound. 7

The composite material being thus built up, the rough edges 'm'ay besawed and smoothed to precise surface dimensions required for the. topand'a protecting edge strip or molding glued against said edges. Anornamental molding may be used for this purpose. V Y 1 i The top andbottom may then be finished bygrinding off its upper surface to atrueplane exactly parallel with its lower surface, care, being takentofleave the composition board facings of substantially the samethickness; This -has the advantage of removing the planished surface ofthe comg position to'expose arelatively raw surface that will takestain, paint or the like, as may be'desired. For the color, :I mayuse-oil .penetrate the fibers and give the desired color. Thecolorsurface maythen be covered with a thin,t'ransparent coat ofpyroxylin,

the gloss'of whichmay be removed by wax,

as above described. Also, as above described,

any desired pictures or ornamentationsmay dicatecertainfeaturesof mymethod and;

lit

the productthereof. In these drawings,

Fig. 1 is aplanview of atop made in accordance with my;invention;,

filler strips may be assembled and glued to the face. of a board of thewood pulp com up beforehand .Fig. 3 is an enlarged sectional detail of Ithe complete product as, for instance, on the 7 line 3'3, Fig. 1.

the completed topof which only the upper composition layer 2 is'visible.1 -Figs; 1 andl2 ind'cate the simplest and mixed with pigment and benzolwhich will accompanying drawings, which are Fig.2 is a schematic viewindicatinghow In Fig. 1, itnwill be understood that 1 is V the moldingor frame glued to theedges of lac cheapest method of assembling. Asbefore stated, the essential for the filler strips, as

4, 5, 6, 7, 8, etc. is that they be uniformly kiln dried and that theybe planed to ex sheet 3, on which are assembled strips enough to coveritand preferably to overlap the edges both at the sides and ends. Whilethe material and size may be the same for all the filler boards,miscellaneous scrap is preferably used because it is cheaper. .As anillustration, the piece 4, Fig. 2, may be or dinarily kiln dried woodfrom a southern gum tree, say 4 inches wide and 3 feet long.

The next piece, 5, may be 3 inches wide of tupelo and it may be only 15inches or so long, the remainder of the length being filled out by anentirely separate piece, 5a. 6 may be oak, 7 may be a 2-inch width ofbeech, etc., etc. The assembler simply has a stack of these fillers ofproper thickness. He takes them one at a time and applies the oppositesurfaces to the glue applying apparatus, not caring whether or not anyglue gets on the side edges. Tests seem to show that the lengthwisestrength is as great or even greater when the strips are not gluedtogether laterally, but they may be so glued if desired. Preferably allthe strips extend beyond the margin ofthe composition sheet both at theends and at the sides. It is immaterial if there be quite substantialspaces up to a quarter of an inch or more between strips, as at 10, Fig.2. V 7

After the sheet or board 00 is thus covered with filler strips, asimilar board as 2, is applied in registry with x, whereupon clamps areadjusted to apply great pressure and so remain for the time necessary toallow the glue to set, say 12 hours. This is facilitated by the natureand depth of the composition employed.

Thereupon the completed structure is removed from theclamps and is sawedalong or, preferably, slightly within the line a, m, to form a perfectlytrue rectangle with vertical edges. Thereupon the frame or moldingstrips 1 are glued about the edges and held in clamps until the glue isset. Finally, the entire top and bottom are sanded. off to true parallelplanes, removing any slight projections of the molding 1. Preferably, aweek or ten days are allowed for the struc turc to set and temper,before the final grindof'the surfaces in the sandpapering ma chine.

The resulting "product" is perfectly non;

warping and has remarkable transverse stiffness. While thestiffnessisnaturally greater, the greater the total thickness of the slab, it willbe found that for equal thicknesses my simple three-ply topv is stifferand stronger than the expensive jointed and built-up fiveply tops of theprior art. I The stiffness,

density'and lue receptive quality of the top and bottoms ieets andprobably also the pre-' cise uniformity of thickness of filler strips,

structure. I u i V, 4

' Inthe specific embodiment shown n F g.

, contribute toproduce a remarkably rigid 3, the composition sheets 2,3, are e-achsubstantially one-eighth inch in thickness and the fillercore three-fourths of aninch, mak

ing the total thickness of the slab one inch.v While precise dimensionsare not the essence of invention and while the thickness of the core maybe increased asmay be desired for the most massive table top and'mayfbedecreased to three-eighths or one-fourth inch or'less, for a cardtable,.it is desirable that the composition sheets bekept thick enoughto ensure board-like stiffness anda tensile strengthsufficient tocompletely control thewarping tendencies ofthe core.

lVhile I prefer to use composition boards made by the above describedprocess, I do not wish my invention to be limited to this pre- 7 cisematerial. Moreover, while the extremely simple, almost haphazard methodof assembling described in connection withFig.

2 is very inexpensive and entirely satisfactory, it is evident that thesame boards similarly applied to a previously built-up core In theparticular case shown, most of the v filler strips are through-extendingand run lengthwise of the completed top, but this is not at allnecessary. Frequently, the waste end of furniture wood used for thispurpose are of short irregular lengths, say 15 inches to 30 inches andit is often desirable to lay them widthwise of the completed top,instead of lengthwise as,ifor instance, in the case of a large tabletop, say, 36 inches by 7 2 inches. Obviously, board sheets of maximumlength, say 48 inches by 96 inches, may be used to build up a singlelarge unit which may be either used as a unit or may be sawed up intosmaller units.

While I have referred to the preferred" thatis one of the reasons why itis highly desirable, if not absolutely necessary, to com- 7 day ofJanuary, A. D. 1928.

pletely protect the edges by Waterproofing expedient-s. In the presentcase the "med-on molding serves this purpose perfect y.

i A' raw'top orbottom surfaceexposed'by the sanding machine will takeWater or La benzolstain or glue but does not soak or transmit it in thedirection in which the sheet Was compressed. Consequently, any stain orfiller, particularly when protected by pyroxylin as above described,makes the'eX-,

posed surfacesabsolutely proof against moisture. 1 a

I claim:

A fabricated three ply panel comprisinga sheet'of the long fiber,grainless composition produced by the high compression of steam explodedwood, reinforcing members below' said sheet and in the form of Woodenstrips of uniform "thickness spaced apart Within limits which willrequire a minimum of material while leaving no part of said sheetunsupported through an area great enough to permit a flexure suificientto overcome the elastic limits of said sheet, a second sheet similar insize and composition to said first sheet below said reinforcing members,the

Whole united by glue and pressure into a unitary structure. a H VSignedat New York city, in the county vof New York, a nd State of NewYork this 4th 1-1 MC E D,

AYMOND

